Temperature changes and changes in the moisture in the air feeding into heating, ventilation, and air-conditioning (HVAC) systems increases the number of micro-organisms in the air, producing increased colonies of certain fungi, viruses, and bacteria, all of which are potentially harmful. Additionally, dirty air ducts and dirty HVAC system components can similarly increase the number of micro-organisms in the air, producing increased colonies of certain fungi, viruses, and bacteria.
HVAC systems in residences, office buildings, as well as hospitals, can be a source of various pathogens, which spread infectious micro-organisms from one zone to another—a principal cause of Sick Building Syndrome, recognized by the World Health Organization as a threat to healthy work and living environments.
The purification of environments can be achieved using reactive oxygen species, including ozone. Ozone has been used to purify air conditioning systems in buildings and to sanitize warehouses where products are stored. Despite its widespread use, this basic technique has the disadvantage of accumulating more ozone than is necessary in the treated environment, requiring the elimination of the excess ozone. Several different improvements in this method have been made in an attempt to control the levels of ozone in the environment being treated.
One such improvement provides high initial levels of ozone to the environment sufficient to produce the desired bacteriostatic or bacteriocidal effect. Later the levels of ozone are reduced so that they do not produce harmful effects to the products being treated or to humans in the environment.
However, the majority of the known systems for purifying closed areas with ozone are based on an ozone generator that utilizes a source of concentrated oxygen, for example bottled oxygen or a known pressurized oxygen generating system utilizing static discharge. When ozone is generated from a source of concentrated oxygen, the level of oxygen in the enclosure may rise along with the level of ozone. The increase in oxygen levels is due to the breakdown of ozone partially into new molecules of oxygen. An increase in the level of oxygen in enclosures containing natural perishable products enhances cellular metabolism and thus is detrimental to the storage of the perishable products.
One known method is applied to substantially closed rooms or rooms with a controlled atmosphere. The substantially closed room includes a closed circuit air conditioning system, such as a cooling system, for the preservation of perishable natural products. A known ozone generator is placed in proximity with the substantially closed room such that the ozone generator can draw in air from within the substantially closed room and liberate ozone into the substantially closed room. In contrast to other known ozonation systems, the known method utilizes oxygen from the air of the room in which the purification treatment is being applied to generate ozone. Because the method converts oxygen from the air into ozone, no increase in oxygen levels is observed in the closed room. Rather, the gaseous equilibrium is shifted so that there is maintenance of the level of oxygen in the enclosure.
The oxidative character of the ozone has a bacteriostatic and fungistatic effect in the short term, followed by a bacteriocidal and fungicidal effect. These effects combine with the lowered metabolism in a temperature cooled environment to reduce ripening, retard spoilage and thus preserve natural perishable products stored in the room.
However, the system does not provide an optimal means for efficiently sanitizing the air within the closed room.